Answer:
C: All students in each grade
Explanation:
It cant be all teachers in the school since at the beginning of the question it says "whether the students" not whether the teachers plus it is not a mxed variety, so this question was sort of trying to catch you off guard
The reason why is if you pick all the boys in each grade then it wouldnt really be random since your picking the gender you want to answer it has to be a mixed variety all ages all genders and so on
Yes! All students in each grade would be a mixed variety since its all ages, all genders, and all grades this answer was a little obvious since they sort of gave you the answer saying "The social studies teacher wants to know whether the students in the entire school"
All students in the social studies club wouldnt be a good answer either since (as i said before) it has to be random and your picking who you want to answer plus since there in the club with the social studie steacher they are more likely to pick what she wants to pick
So the answer would be C: All students in each grade